1. Field of the Invention
The present invention is related to a printed wiring board having a pad, which is formed on the upper-surface side of a resin insulation layer, for mounting an electronic component such as a semiconductor element; a conductive circuit (including an external connection terminal), which is formed on the lower-surface side of the resin insulation layer, for connection with an external substrate; and a via conductor, which is formed in the resin insulation layer, for connecting the pad and the external connection terminal. The present invention is also related to a method for manufacturing such a printed wiring board.
2. Discussion of the Background
Japanese Laid-Open Patent Publication 2000-323613 (Patent Publication (1)) discloses a printed wiring board (multilayer substrate) which is formed without using a core substrate by laminating resin insulation layers and conductive layers alternately. In the multilayer substrate of Patent Publication (1), pads for a semiconductor element are formed on the upper-surface side, and pads for external connection terminals are formed on the lower-surface side. The pads for a semiconductor element are embedded in the outermost insulation layer of the upper-surface side. The surfaces of the pads for a semiconductor element are positioned at the same level as the surface of the outermost layer, or lower than the surface of the outermost layer. On the other hand, the pads for external connection terminals are formed on the outermost insulation layer on the lower-surface side.
The contents of Japanese Laid-Open Patent Publication 2000-323613 are incorporated herein by reference in their entirety.